Radiologiczna ocena ślimaka i zachowanie słuchu u dzieci leczonych za pomocą wszczepienia implantu ślimakowego Cochlear Nucleus z elektrodą prostą CI422

Cochlear implantation is becoming more and more widely used in clinical practice. In this study we’ve verified the hypothesis that cochlear implantation according to individually calculated depth of insertion affects hearing preservation in children with preoperative substantial hearing. In the retrospective analysis of 19 children implanted with Cochlear Nucleus CI422 electrode in Institute of Physiology and Pathology of Hearing in Warsaw between 2010–2011 the relation between cochlea size and insertion depth angle was calculated on the basis of radiological data and hearing preservation rate, calculated according to Hearing Preservation Classification. [1] Hearing Preservation rate for the whole group at activation was 73%, after 24 months – 67%. Mean value of insertion depth angle was 375° (SD = 17°); mean value of calculated length of cochlear duct was 34.67 mm (SD = 1.91); mean calculated linear insertion depth of the electrode array was 23.1 mm (SD = 1.62). We did not find any statistically significant difference between hearing preservation rate and angle of insertion and between hearing preservation rate and linear insertion depth for the analysed group in any of three intervals: activation, 12 months follow up and 24 months follow up. Preoperative measurement of cochlea size and its specific parameters, like linear insertion depth, do not influence hearing preservation after implantation. Low level of hearing preservation rate in some cases cannot be explained with intracochlear position of the array (>450°) in computed tomography.